HIFE-haptic interface for finger exercise

A haptic device with two active degrees of freedom and a tendon-driven transmission system was designed, built, and tested. It was constructed as a mechanism with a small workspace that envelops a finger workspace and can generate forces up to 10 N, suitable for finger exercise. Kinematic and dynamic model equations of the haptic device are presented in the paper. The control strategies, the implementation of the application on a PC, the real-time millisecond-class control environment, running under the MS Widows operating system, and safety mechanisms are described. Also, the duration test for the maximum sustained output force, and validations of accuracy of the output force and the consistency of the followed path, were performed. The performance, accuracy, and safety of the device were found to be very good, which makes the device suitable for rehabilitation purposes.